From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 16 Mar 2001 12:49:59 +0100 From: Francois Romieu Subject: Re: Non PCI bursting cards should go to the trash can Message-ID: <20010316124959.A407@se1.cogenit.fr> References: <20010315062806.24508.qmail@nwcst340.netaddress.usa.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20010315062806.24508.qmail@nwcst340.netaddress.usa.net>; from qureshi_jawad@usa.net on Wed, Mar 14, 2001 at 11:28:06PM -0700 Sender: owner-linux-mm@kvack.org Return-Path: To: Jawad Qureshi Cc: linux-mm@kvack.org List-ID: Jawad Qureshi ecrit : [...] > I am facing some problems with the pci. I have two questions about Pci. > First is that > 1-how one can explicitly specify to brust on the pci device; > 2-We have a custom made pci card . The problem is that the transfer on this > card is slow. I am making 40 double word transfers from the fifoes on the > board to the memory. The pci card does not allow brusts. These transfers are > taking almost 32us. Can any body tell why this much time is taking place. 32us/40 = 800ns. PCI at 33MHz, cycle = 33ns -> 24 cycle/access. The *address* phase of a PCI r/w cycle eats 6 cycles for himself at least. It looks rather normal. -- Ueimor -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/